body {
    margin: 0;
    background: #4b4b4b;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

div {
    width: 0.875rem;
    height: 5rem;
    background: #fff200;
    margin-left: 0.875rem;
    animation: bar-loading 1s infinite alternate;
}

div:nth-child(2) {
    animation-delay: -0.2s;
}

div:nth-child(3) {
    animation-delay: -0.4s;
}

@keyframes bar-loading {
    0% {
        transform: scaleY(0.5);
    }
    100% {
        transform: scaleY(1);
    }
}